1. Field of the Invention
The present invention relates to an apparatus and method for reading a multi-color original with a solid-state imaging device such as a charge-coupled device to obtain image information containing color information.
2. Description of the Prior Art
There is already known image processing in which an original image is read as electric signals by a solid-state image device and the image information obtained as electric signals is utilized for reproduction of the image on a recording material such as paper, display on a display device such as a cathode ray tube or transmission to a distant location for example through a facsimile device. Such image processing has mostly been based on monochromatic processing of the image. Recently, however, there is being proposed processing of image information bearing color information by reading also such color information from the original.
The image information bearing color information is obtained from a multi-color original generally by color decomposition of the original with plural imaging devices respectively positioned in different optical paths having color separating filters of different color transmission characteristics. In such method, however, a slight positional aberration or difference in sensitivity between the imaging devices may cause color distortion which is extremely difficult to correct. Also the use of plural units of expensive imaging devices such as charge-coupled devices inevitably raises the cost of the apparatus.
Also as an alternative method for obtaining image information bearing color information with a single imaging device, the color separation for example for industrial television cameras can be achieved by rotating a filter disk having plural colors at a high speed in front of the imaging device. However such method requires a complicated large-sized mechanism for accurately rotating the filter disk at a high speed, and is inevitably associated with mechanical noises.